For some people, chemotherapy causedsubtle problems - like making multitaskingmore difficult.Image: iStockphoto

A condition that affects the memory and concentration of cancer patients undergoing chemotherapy is sustained in a subgroup of patients, compromising their ability to function and long-term quality of life, according to research presented today (18/11) at a major cancer conference.

Dr Janette Vardy from the Sydney Cancer Centre, told the Clinical Oncological Society of Australia Annual Scientific Meeting ‘chemofog’ had previously been assumed to be temporary, but for 20 to 30 per cent of patients, it had been shown to be ongoing.

“It is only in the last 10 years that we have recognised ‘chemofog’ or ‘chemobrain’ as a condition,” Dr Vardy said. “For a long time some oncologists didn’t believe it was real and it was all in the mind.

“The impairment can be subtle, but it can have a significant impact on daily living, affecting things like the ability to multitask. However, newer imaging studies have shown that there can be differences in blood flow and metabolic activity in people who have had chemotherapy when they are performing memory tasks.”

Dr Vardy said that now the medical profession had largely been convinced that chemofog was real, they were confronted with the new reality that it could be a persistent side-effect and without an effective treatment.

According to Dr Vardy, the issue was further complicated by research showing that the same condition was also present in a number of patients before treatment.

“Prospective studies report that up to 30 per cent of patients with breast and colorectal cancer have cognitive impairment prior to receiving chemotherapy,” she said. “This suggests that in many cases, other factors such as the cancer itself or stress may contribute, rather than it being the treatment.”

Dr Vardy said a longitudinal study of patients in Australia and Canada was currently underway in a bid to find answers. “Once we have a better idea of the causes, we will be in a much better position to develop effective treatments.”